Tech

Severed Battery Heals Like Skin

The next generation of wearable tech won't be just another smartwatch or smart sports bra. If a team of researchers from the University of of California San Diego is right, tomorrow's wearable gadgets will look, feel and even heal like skin.

"The wearable devices of the future will be very much like a second skin," said Amay Bandodkar, co-author of a new paper on self-healing circuitry. "They'll be so thin and so well-integrated with your body that you won't even know that they're there."

Imagine a powerful sensor the size of a postage stamp that could monitor a patient's vital signs from home. Or a temporary tattoo that could control your smartphone.

While a PhD candidate at UCSD, Bandodkar and his advisor Joseph Wang experimented with making printed electronic circuits more flexible, soft, stretchable and "skin-like." Printed electronics are already a $30 billion industry pursued by the likes of Intel and Xerox. But the biggest problem with printed electronic circuitry is that it's super fragile.

"If a printed electronic device gets damaged today, you have to throw it away," said Bandodkar. "But if it had the ability to self heal, like our skin, then you could keep using it over and over again."

WATCH VIDEO: Self-Healing Tech of the Future

Researchers have been chasing the grail of self-healing circuitry for years, but the best solutions so far employed chemical reactions that had to be triggered from the outside and took hours or even days to repair a single damaged connection.

Bandodkar and Wang wanted something simple, cheap and fast. What they found was magnets.

In Wang's nanobioelectronics lab at UCSD, they ground up some inexpensive neodymium magnets into microscopic particles, then mixed the pulverized magnets with graphite and solvents to create an electronic ink. They printed a simple battery with the magnetic ink and put it to the test. The results were remarkable.

The magnetic circuits could autonomously heal a cut as wide as 3 millimeters in just 50 milliseconds. No chemical reactions, no outside intervention, just the magical attraction of magnets. Bandodkar and Wang repeated the tests, severing the circuit again and again at the same location, but it always healed itself.

"These strong magnetic properties last for decades and decades," said Bandodkar. "The self-healing process could last for a lifetime."

The two researchers' real interest is in implantable medical devices. They see their self-healing circuits being used to print next generation pacemakers and internal diagnostic tools that never have to be removed or repaired. But first they'll have to test how the human body responds to these new types of magnetic materials.

Bandodkar also recognizes the potential trouble of a magnetically charged circuit coming into contact with metal or another electromagnetic field. He's exploring a cheap fix involving a paint that shields circuitry from electromagnetic interference.

For his next magic trick, Bandodkar is experimenting with methods that would not only reconnect a severed circuit, but erase any trace of the damage.

"We want to see how we can make the connection permanent again," said Bandodkar, now a post-doc at Northwestern University. "We have to incorporate some sort of chemistry so that once the magnet comes together, the chemical reaction takes it back to its initial state. No crack or scar at all."